NAND Gate
| Input A | Input B | Output |
|---|---|---|
| false | false | true |
| false | true | true |
| true | false | true |
| true | true | false |
A NAND gate (sometimes referred to by its extended name, Negated AND gate) is a digital logic gate with two or more inputs and one output with behavior that is the opposite of an AND gate. The output of a NAND gate is true when one or more, but not all, of its inputs are false. If all of a NAND gate's inputs are true, then the output of the NAND gate is false.
The truth table for a NAND gate with two inputs appears to the right.
Symbols
Each of the symbols below can be used to represent a NAND gate. There are multiple international stnandards defined, and one may preferred over the other in your region of the world.
| ASNI / IEEE | IEC |
|---|---|
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Live Example
Try the following interactive example to see for yourself how a NAND gate behaves.
Please ensure that Adobe Flash Player 10 or greater is installed.
Further Reading
To learn more, check out the following external resources:
NAND gate on Wikipedia
Multiple-input gates on All About Circuits
Derived Logical Functions and Gates at Play-Hookey




